Electric darning apparatus



Aug. 8, 1950 G. E. BoMBoNATo ELECTRIC DARNING APPARATUS 2 Sheets-Sheet 1 Filed Jan. 14, 1949 E WH All@ 8, 1950 G. E. BOMBONATO 2,517,627

ELECTRIC DARNING APPARATUS Filed Jan. 14, 1949 2 Sheets-Sheet 2 Patented Aug. 8, 1950 ELECTRIC DARNIN G APPARATUS Gottardo E. Bombonato, Geneva, Switzerland Application -lianuary 14, 1949, Serial No. 70,957 In Switzerland May 5, i948 (Cl. (i6- 1.5)

6 Claims. l

This invention relates to electric darning apparatuses and more particularly to electric darning apparatuses for monding ladders in stockings, socks, and other hosiery.

It is an object of the invention to provide a simple and reliable apparatus which is electrically driven and includes a driving mechanism enclosed within a portable needle carrier for reciprocating the needle plunger thereof.

Other objects and advantages of the invention will appear from the following description.

In the accompanying drawings there is shown a darning apparatus embodying the invention.

Fig. l is a longitudinal sectional View taken on the line I-I of Fig. 2, the needle plunger being in its foremost position.

Fig. 2 is a longitudinal sectional View taken on line II-II of Fig. 1, the needle plunger being in retracted position and the needle being covered by a removable cap.

Fig. 3 is an elevational View of the driving mechanism.

Fig. 4 diagrammatically illustrates the electric control device.

Fig. 5 is a sectional View of a detail on enlarged scale.

The ladder-mending apparatus shown in the drawing comprises a handle or casing I to the rfront end of which is screwed a, bushing 2 having a front opening of restricted diameter through which passes the needle plunger 4 carrying the conventional mending needle 3. The needle plunger 4 is imparted a rapid reciprocating movement in the longitudinal direction by a driving mechanism which comprises a damping device 5, a driving rod 6, a crank 'I and a gear train 8, 9, IIJ. This driving mechanism is actuated by an electric motor II.

The damping device 5 includes a cylindrical housing I2 (Figs. 1 and 2) whose front cover I6 is provided with a central aperture for the passage of the needle plunger 4. The rear extremity of the needle plunger 4 is formed with an enlarged head I3 subjected to the opposite forces of two coil springs I4 and I5 bearing on the front cover I6 and on the bottom I'I of the housing I2 respectively. The springs become compressed at each half of an oscillation of the needle. The housing I2 is slidably mounted within the bushing 2 and carries at its rear extremity a transverse screw i8 about the smooth portion of which is pivoted the front end of the rod 6, whose rear end is hingedly connected to the crank-pin I9 of the crank 'I. Crank 'I is rigidly secured to the h-ub 20 of the gear 8 pvoted about a pin 2l secured to a plate 22. The gear 8 meshes with a gear 9 pivoted on pin 23 and gear 9 meshes with the driving pinion I0 secured to the driving shaft 24. The driving shaft 24 (Fig. 5) is rotatably supported on the one side in a bearing 25 forced in the plate 22 and, on the other side in a bearing 26 forced in a second plate 27. The rotor of the motor II is mounted on the driving shaft 24. It comprises a sleeve 23 loosely mounted on the shaft 24 and carrying on the one hand, a three-armed laminated armature 29, each arm carrying a winding 3U, and on the other hand a collector with three segments 3| each of which is electrically connected toa winding 30. The sleeve 28 is held axially in Vplace by a shoulder 32 of the shaft 24 and by the inner face of the bearing The two plates 22 and 2l are held spaced apart by spacing braces 33 only one of which is shown in Fig. l. The armature rotates between the poles 34 oi a horseshoe-shaped stator 35 carrying a field coil 36. The rotor is fed with electric current by means of carbons 3l guided in carbon-holders 38 and pressed by springs 39 against the segments 3| of the collector.

The rotor is mechanically connected to the shaft 24 by means of a Coupling adapted to limit the maximum couple which can be transmitted. In the embodiment shown in the drawing this maximum couple is dened by the friction which opposes the relative angular displacement of the two pieces. The coupling includes an arched wire spring 4D the ends of which engage in holes 4I provided in the shaft 24 at right angle to the axis thereof and whose middle portion, lodged in a longitudinal groove 42 oi the shaft 24, bears on the cylindrical inner surface of the sleeve 28.

The control device comprises a manually operable pusher 43 which operates a lever 44 hingedly connected by its one end to the plate 21 and carrying a part d5 of a locking device 45-45. The pusher 43 operates further a movable contact 4'I of a switch whose xed contact 48 is carried by the plate 2'1. A spring Ill acting on the lever 44 tends to maintain the two parts of the locking device in operative engagement with each other and to hold the switch #Il- 48 in open position. The part 46 of the locking device is formed as a part of an oscillating lever 50 pivoted about a pin 5l carried by the plate 2'1 (Fig. 3). This oscillating lever is submitted to the action of a spring 52 and carries, on the one hand, a control head 53 intended to cooperate with the extremity of the crank-pin I9, and, on the other hand, a movable contact 54 of another switch whose stationary contact 55 is carried by the plate 2'1.

The Figure 4 in which the above described members are shown diagrammatically, illustrates the electric and mechanical connections of this control device. The lead 5B is connected to one extremity of the eld coil 36 of the stator 35, the other extremity of this field coil being connected to one of the carbons 31. The second carbon 31 is electrically connected to the contacts 48 and 54 of the two switches, while the other contacts 41 and 55 of those switches are connected to the return conductor 51.

The control device further comprises a stop motion device intended to stop the motor in a position corresponding to the retracted position of the needle 3 (Figs. 2 and 3). This stop motion device comprises a rst abutment 58 carried by the lever 44 and a second abutment 59 constituted by the outwardly bent extremity of a split ring 50 mounted in a groove 6I of a disc 62 secured on the shaft 24.

The operation of the apparatus described is as follows:

At rest, the various members of the control device are in the relative position shown in Fig. 3. When a pressure is exerted on the pusher` 43, the lever 44 is displaced against the action of its return spring 49 thereby releasing the lever 50 which begins to oscillate under the action of its spring 52 until the contact 54 meets the contact 55 thus closing the first switch and energizing the motor II; on the other hand the abutment 58 is displaced away from the abutment 53 which is dependent on the driving shaft 24, thus releasing the latter for rotation.

As a result, as soon as the motor II is energized and the shaft 24 released, the rotor begins to rotate in the clockwise direction thus driving the shaft 24 by friction owing to the spring 40 putting a radial pressure on the sleeve 28 and holding it in contact with the shaft 24.

The housing I2 is then imparted a rectilinear reciprocating movement. The needle plunger 4 follows this reciprocating movement; however, owing to the springs I4 and I5 being interposed between the housing I2 and the needle plunger 4, the movement of the latter will not be Sinusoidal, which will procure some advantages for ladder mending. Owing to the bulk of the plunger and needle assembly 4-3, the springs I4 and :I5 becomealternatingly compressed and released at each change of direction of the housing movement; a relative displacement occurs between the plunger 4 and the housing I2, so that the instantaneous velocities of the needle 3 do not correspond to those of the housing I2 and the stroke of the needle 3 is different from that imparted to the housing I2 by the rod 6.

At each revolution of the motor the crank-pin I9 cooperates with the control head 53 and repels the oscillating lever 59 against the action of its return spring 52, thus causing momentaneous opening of the rst switch 54-55 Owing to the inertia of the moving parts, the motor and the mechanism do not stop, the interruption of the current supply being of too short a duration; however as a result of these repeated interruptions, the speed is reduced.

If a heavier pressure is exerted on the pusher 43, permanent closure of the second switch 41-48 connected in parallel to the contacts 54 and 55 of the rst switch will be performed. The motor II will thus be fed permanently and run at full'speed. Thus the user is given the possibility yto obtain, by simply exerting a more or less heavy pressure on the control pusher 43, two different speeds of the needle 3.

To stop the motor and the whole mechanism, it is suicient to let go the pusher 43 which is returned back by the spring 49 into a position of rest in which a shoulder 63 of pusher 43 runs against the outer casing I. The contact 41 leaves the contact 48 and the lever 44 oscillates in a counter-clockwise direction under the action of the spring 49. The motor is then fed through the first switch 54-55 and actuates the needle 3 further. However, at the iirst passage of the crank-pin I9 on the control head 53, the contacts 54 and 55 are drawn apart, and soon after the passage of the part 46 under the hook of the part 45, the lever 44 is brought back into the position shown in Fig. 3 by the return spring 49, with the result that when the crank-pin I9 leaves the control head 53, the part 53 is placed on the path of the part 46, thus preventing lever from oscillating under the action of its spring. Thus the first switch 54-55 remains open and the motor is no more energized. However, owing to the inertia of the moving parts, the needle 3 runs further; as the lever 44 is in the position shown in Fig. 3, the abutment 58 is placed on the path of the hook 59 with the result that the mechanism is suddenly stopped a little while after the crank-pin I9 has left the head 53 and is thus approximately in the position shown in the Figures 2 and 3, in which the needle is in retracted position.

The moving part which has the largest inertia bulk is the rotor of the motor. The moment of inertia of the rotor running at several thousands of revolutions per minute and stopped fiercely would be sufficient to damage the driving mechanism and the control device. In order to avoid such deteriorations, the rotor is, as described in the foregoing, connected to the shaft 24 through the intermediary of a coupling which limitates the transmissible couple. Thus, when the shaft 24 is stopped suddenly by the lug 59 running against the stop 58, the moment of inertia which tends to rotate the rotor is such that it is able of overcoming the friction produced between the shaft 24 and the sleeve 28 by the spring 4l), with the result that the rotor keeps rotating about the driving shaft without driving the latter and soon comes to a stop under the braking action due to the friction. By adjusting the angular position of the lug 59 it is quite easy to cause the `driving shaft to be stopped in the position shown in Fig. 3 wherein the needle is rectracted.`

Furthermore, as the driving couple necessary to drive the needle is very small, a small sized motor of the kind generally used in electric toys will .be vsuicient. The whole apparatus can be constructed in very small dimensions and the casing I can be formed as a handle to hold the apparatus in the users hand and guide the needle.

What .I ,claim is 1. An Velectric darning apparatus comprising a casing, a reciprocable mending needle and needle plunger assembly, an electric motor and a driving mechanism within said casing for reciprocating said needle and plunger assembly, a manually operable `outer control member on said casing, .a switch inserted in an electric circuit for said motor, a spring normally holding said switch in closed position, a locking device for holding said switch open, said locking device being operable by said control member, .and a movable abutment subjected to the Vaction of said control member, said movable abutment being adapted to vbe brought into the path of a movable part of said driving mechanism to stop said mechanism in a predetermined position wherein the needle is retracted.

2. An electric darning apparatus as claimed in claim l wherein a damping device is interposed between the driving mechanism and the needle.

3. An electric darning apparatus as claimed in claim l wherein a damping device is interposed between the driving mechanism and the needle, said damping device comprising two compressible springs interposed between the member of the driving mechanism which actuates the needle holder and the needle holder, each of said springs acting in one direction of the needle movement.

4. An electric darning apparatus as claimed in claim 1 wherein the driving mechanism comprises a coupling connecting the rotor of the motor to the driving shaft to limit the maximum couple which can be transmitted.

5. An electric darning apparatus as claimed in claim 1, wherein the switch is submitted to the action of a movable member adapted to open it at least once at each revolution of the mechanism, whereby to reduce the speed of the motor.

6. An electric darning apparatus as claimed in claim 1, comprising a second switch operable by the control member against the action of a return spring, said second switch being connected in parallel with the iirst switch and being adapted to be closed by an additional displacement of the control member after releasing of the locking device, whereby to attain the full speed of the motor.

GOTTARDO E. BOMBONATO.

REFERENCES CITED The following references are of record in the file of this patent:

FOREIGN PATENTS 20 Number Country Date 215,124 Switzerland Sept. 1, 1941 877,533 France Sept. 7, 1942 

